diff --git a/pkgs/development/tools/ocaml/utop/default.nix b/pkgs/development/tools/ocaml/utop/default.nix
index c50e6a108bda..9e394751761a 100644
--- a/pkgs/development/tools/ocaml/utop/default.nix
+++ b/pkgs/development/tools/ocaml/utop/default.nix
@@ -61,8 +61,8 @@ stdenv.mkDerivation rec {
       --argv0 "" \
       --prefix CAML_LD_LIBRARY_PATH ":" "${get "CAML_LD_LIBRARY_PATH"}" \
       --prefix OCAMLPATH ":" "${get "OCAMLPATH"}" \
-      --prefix OCAMLPATH ":" $(unset OCAMLPATH; addOCamlPath "$out"; printf %s "$OCAMLPATH")
-
+      --prefix OCAMLPATH ":" $(unset OCAMLPATH; addOCamlPath "$out"; printf %s "$OCAMLPATH") \
+      --add-flags "-I ${findlib}/lib/ocaml/${stdenv.lib.getVersion ocaml}/site-lib"
    done
    '';